Icy World Surface Composition
The surfaces of outer solar system moons record billions of years of geological and chemical evolution in their spectral signatures. I use imaging spectrometer data — primarily from Cassini VIMS — to map surface composition at regional scales, and I have developed a geospatial-topological clustering approach that identifies spectrally distinct terrain units without imposing assumptions about what those units should look like. My first-author paper in Icarus (2024) applied this method to Titan's equatorial region, revealing the spatial relationships between dune fields, interdune substrates, and compositionally distinct exposures that trace the history of surface-atmosphere interaction at low latitudes.
I am extending these methods to targets observed by JUICE/MAJIS (Ganymede) and plan to apply them to Europa Clipper data. The core question is the same across all these bodies: what is the spatial organization of surface materials, and what does that organization tell us about the processes — cryovolcanic, tectonic, radiolytic, depositional — that produced it?
Atmospheric Hazes and Aerosols
Titan and Pluto both host complex atmospheric haze layers that shape their energy budgets, drive photochemistry, and deposit organic material onto their surfaces. I study these hazes through limb-scatter observations — measurements of sunlight scattered by aerosol particles at the edge of a world's disk — which constrain particle size distributions and number densities as a function of altitude.
My work on Pluto (PSJ, 2021) used New Horizons/MVIC limb-scatter data to retrieve haze abundance and particle size profiles, providing some of the first quantitative constraints on Pluto's haze microphysics. On Titan (PSJ, 2022), I identified stratospheric haze bands in Cassini VIMS data and demonstrated that their morphology traces large-scale meridional circulation patterns in Titan's middle atmosphere. More recently, I co-authored a paper with Conor Nixon and collaborators in Nature Astronomy characterizing Titan's atmosphere in late northern summer using JWST and Keck observations.
Voyager True-Color Reprocessing
The Voyager 1 and 2 spacecraft returned some of the most iconic images in the history of exploration, but the original data products were calibrated with 1970s-era tools and have never been systematically reprocessed with modern photometric and colorimetric methods. I am developing a pipeline to produce perceptually accurate true-color imagery from the Voyager Grand Tour archive — not just cosmetically enhanced mosaics, but radiometrically grounded RGB composites that faithfully represent what a human eye would see at Jupiter, Saturn, Uranus, and Neptune.
This project builds a pixel-level database of the Voyager imaging archive and applies my existing spectrophotometric and geospatial-topological methods to the reprocessed data, enabling new science on targets like Europa chaos terrain and Triton plume microphysics that were previously limited by data quality.
Methods: Spectral Clustering and Phase Function Inversion
Two methodological threads run through my work. The first is geospatial-topological spectral clustering: a framework for identifying compositionally distinct terrain units in hyperspectral data by combining multivariate statistics (PCA, k-means) with geospatial topology — the spatial adjacency and boundary relationships among clusters — to produce maps that are both spectrally rigorous and geologically interpretable. The second is limb-scatter phase function inversion: a radiative-transfer technique for retrieving aerosol microphysical properties (size, shape, abundance) from the angular dependence of scattered sunlight observed at a body's limb. Both methods were developed and validated in my published work and are designed to be portable across missions and targets.
Mission Involvement
I have been a member of the Europa Clipper science team since 2015 and contributed to the CAESAR comet sample return and Oceanus Titan orbiter concept mission studies. I also spent several years as a contract researcher at JPL, where I performed photometric calibration for Mars Perseverance cameras and generated digital terrain models of comet 67P/Churyumov–Gerasimenko using photoclinometric methods.